ART. 4. REVISION OF THE FAMILY THEREVIDAE—COLE, 131 
The femora are black, with long but sparse white pile; the tibiae 
and tarsi are pale yellowish brown, the apices hardly darkened at all. 
The wings are pure hyaline, the stigma brownish, the veins thin and 
the upper fork of the third vein turned upward. 
Type locality Las Vegas Hot Springs, New Mexico, May 17. 
Type.—In the United States National Museum, Cat. No. 26029. 
THEREVA CONCAVIFRONS Kréber. 
1914. Thereva concarvifrons Kroser, Beiheft z. Jahrb. Hamb. Wiss. Anstalten, 
vol. 31, p. 70. 
Female.—Length 12mm. The head is almost golden yellow to- 
mentose, the face becoming whitish, the vertex merging to brownish; 
between the two colors is a dull black band which reaches from one 
eye to the other, slightly bulging and quite far from the ocelli; in 
certain lighting it disappears; in this case below the lowest ocellus a 
similar band appears, which however is far from the eye margin. 
This band is the margin of a quite noticeable frontal concavity. The 
first antennal joint is black, gray tomentose, the second with a brown- 
ish tone, the third pure brown, reddish at the base. 
The mesonotum is brownish yellow tomentose, with thick close- 
lying, golden yellow, almost wooly pile. Thescutellum appears to be 
reddish, with tomentum and pile like the thorax. The mesonotum 
has two faint stripes and a brown median vitta. The pleura are light 
gray, very sparsely brassy yellow pilose. The halteres are brownish, 
with a reddish yellow stem. 
The abdomen is shining reddish yellow, the second to the fifth ter- 
gites with more or less rounded off, shining black anterior marginal 
spots. The venter is plain reddish yellow, the second to the fourth 
segments with faint, silky borders as on the upper side. The legs are 
wholly reddish yellow, the tarsi hardly darkened at all. The wings 
are tinged pale brownish, the veins noticeably bordered, the stigma 
very faint. 
Type locality.—Rio Ruidoso, New Mexico. 
Type.—In the United States National Museum, Cat. No. 26026. 
THEREVA FLAVOHIRTA Kréber. 
1914. Thereva flavohirta Kroser, Beiheft z. Jahrb. Hamb. Wiss. Anstalten, vol. 
31, p. 70. 
Female——Length 12.5 mm. Very near 7. flavicauda Coquillett 
and duplicis Coquillett. The antennae are wholly pale yellowish red. 
The callosity consists of two shining black, quite convex spots. The 
pile of the antennae and the face pale reddish yellow. 
The mesonotum is sparsely grayish yellow pilose. The legs are 
wholly pale yellowish red, the last tarsal joint scarcely darkened. 
Abdomen on the first to the fourth segment largely blackish gray. 
60466—23—Proc.N.M.vol.62——22 
